Slides for endless belt conveyors

ABSTRACT

Slides for use on an endless belt conveyor belt and wear pads for use on slides for endless belt conveyors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/600,887, filed on Nov. 17, 2006, the contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to slides for endless belt conveyors and wearpads for use on slides for endless belt conveyors.

2. Discussion of the Prior Art

Slides, which have been referred to as idlers have been used for sometime to support conveyor belts. For example, U.S. Pat. No. 6,854,593issued to Boudreau et al on Feb. 15, 2005, discloses a slide referred totherein as a pad-type idler, for slidably supporting a continuousconveyor belt. The pad-type idlers are supported on a metal supportabove a base. When conveying a liquid-containing substance, e.g. in thefood processing industry, liquid falls onto the slides where itaccumulates. The presence of a liquid between the belt and the slidesresults in drag (skin friction drag) between the belt and the slideswhich causes the belt to slow down or stop.

U.S. Pat. No, 5,799,780 issued to Steeb et al (hereinafter Steeb) onSep. 1, 1998, discloses a slide, referred to therein as a wear bar, forslidably supporting a continuous conveyor belt. The first embodiment ofSteeb is a feed idler assembly, which includes a generally U-shapedframe defined by a base, a pair of legs on opposite ends of the base anda pair of shorter intermediate supports between the legs. Plates areattached to the top ends of the legs of the intermediate supports. Wearbars are attached to the tops of the plates. A conveyor belt slidingover the wear bars forms a trough which is useful for conveyingmaterials in the manufacturing and mining industries.

The fixed wear bars of Steeb are intended to replace rotatable idlerrollers. The Steeb patent discloses two different types of wear bars,namely those used for a feed idler assembly (see FIGS. 8 a to 8 c inparticular) and one for a return idler assembly (see FIGS. 11 a to 11c). The feed idler wear bar has a flat top surface and tapered sidesurfaces. The return idler is a flat plate. The Steeb return idlerscause the edges of the conveyor belt to wear, because the belt has aslightly bowed profile upon its return and accordingly contacts theedges of the return idlers.

GENERAL DESCRIPTION OF THE INVENTION

In one aspect, the invention relates to a wear pad for use on a slide ofan endless track conveyor belt comprising an elongated body having aflat top surface for slidably supporting a conveyor belt during travelof the belt over the top surface between leading and trailing edges ofthe top surface; and a plurality of grooves in said top surfaceextending between the leading and trailing edges of the body fordischarging liquid falling onto the top surface, whereby drag betweenthe wear pad and the belt is reduced.

In another aspect, the invention relates to a slide for use on anendless belt conveyor, said slide comprising a crossbar extendingperpendicular to the path of travel of the endless belt; and a wear padon said crossbar for supporting said belt during travel of the belt,said wear pad extending perpendicular to said path of travel; a spacerbetween said pad and said crossbar for spacing said pad from saidcrossbar; and retaining means for retaining said pad and spacer on saidcrossbar.

In another aspect, the invention relates to a slide for use on anendless belt conveyor, said slide comprising a crossbar extendingperpendicular to the path of travel of the endless belt; the top of saidcrossbar having a hole therethrough; a wear pad on said crossbar forsupporting said belt during travel of the belt, said wear pad extendingperpendicular to said path of travel and having a threaded holetherethrough, a synthetic fluorine-containing resin bolt in saidthreaded hole extending through said hole in said crossbar; and lockingmeans for retaining said pad on said crossbar.

In another aspect, the invention relates to a return slide for use on anendless belt conveyor, which includes a pair of rollers and an endlessbelt extending around said rollers, said slide comprising a base forextending perpendicular to the path of travel of the endless beltbeneath said rollers; and a wear pad on said base for supporting saidbelt during travel of the belt beneath said rollers, said wear padhaving a top surface which is convex along its length for positioningbeneath an endless belt with the pad extending perpendicular to saidpath of travel.

In another aspect, the invention relates to a hanger assembly used forsuspending a return slide from an endless belt conveyor frame comprisinga hanger plate having a top end for suspending the hanger from theconveyor frame; a bottom end for supporting one end of a return slide; akeyhole slot in said bottom end for receiving a bar for connecting thehanger plate to one end of a return slide; and a clip for locking saidbar in said slot.

In another aspect, the invention relates to a hanger assembly used forsuspending a return slide from an endless belt conveyor frame comprisinga hanger plate having a vertical top end portion; a flange on said topend portion for suspending the hanger from the conveyor frame; a webconnected at one end to a lower end of said top portion for extendinginwardly towards one end of a conveyor slide; a vertical bottom endportion connected to a second end of said web, a keyhole slot in saidbottom end portion for receiving a bar for connecting the hanger plateto one end of a return slide; and a clip for locking said bar in saidslot.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described below in greater detail with reference to theaccompanying drawings, wherein:

FIG. 1 is a schematic side view of an endless belt conveyor of the typewhich can employ a wear pad and a slide in accordance with theinvention;

FIG. 2 is a front view of a slide assembly incorporating a wear pad inaccordance with the invention;

FIG. 3 is an end view of the wear pad of FIG. 2 mounted on a crossbar ofthe slide assembly of FIG. 2;

FIG. 4 is a front view of the wear pad and crossbar of FIG. 3;

FIG. 5 is a top view of the wear pad of FIGS. 3 and 4;

FIG. 6 is a cross section taken generally along line 6-6 of FIG. 5;

FIG. 7 is a front view of another embodiment of a wear pad in accordancewith the invention;

FIG. 8 is a side view of another embodiment of a wear pad in accordancewith the invention;

FIG. 9 is a top view of the wear pad of FIG. 8;

FIG. 10 is a side view of a mounting bolt of the wear pad of FIG. 8;

FIG. 11 is a top view of the mounting bolt of FIG. 10;

FIG. 12 is a partial section bottom view of a section of a crossbaraccording to the invention onto which the wearbar of FIG. 8 can bemounted;

FIG. 13 is a partial section view taken along line A-A′ of FIG. 12;

FIG. 14 is a partial-section view taken along line B-B′ of FIG. 13;

FIG. 15 is a bottom view of the crossbar of FIG. 13;

FIG. 16 is a front view of a return slide in accordance with theinvention and used in the conveyor of FIG. 1;

FIG. 17 is a cross section taken generally along line 17-17 of FIG. 16;

FIG. 18 is a side view of a hanger for mounting the return slide ofFIGS. 16 and 17 on a conveyor;

FIG. 19 is a top view of a bar for connecting the hanger of FIG. 18 to aconveyor frame;

FIG. 20 is an isometric view of a clip for retaining the ends of thereturn slide in the hanger of FIGS. 18 and 19;

FIG. 21 is a side view of the hanger of FIG. 18 with the clip of FIG. 20in the use position; and

FIG. 22 is an end view of the clip and hanger of FIG. 21.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, the slides and wear pads of the present inventionare intended for use in a conveyor assembly of the type including aninclined endless belt for receiving material to be conveyed from a chute2 located above the belt. The belt 1 passes around a tail pulley 3 and adriven head pulley 4. The pulleys 3 and 4 include axles 6 and 7 mountedin pillow block bearings 8 and 9, respectively. The bearings 8 and 9 aremounted on the ends of a frame indicated generally at 10, which includesa plurality of legs 12 and sides 13 (one shown) supported by the legs.

During travel over the top of the pulleys 3 and 4, the belt 1 issupported by transition slides 14 and troughing slides 15. When passingbeneath the pulleys 3 and 4 the belt is supported by return slides 17.Each of the transition and troughing slides 14 and 15 includes a framedefined by a tubular base 18 with plates 19 on the ends thereof formounting the assembly on the main frame 10 of the conveyor. The top endsof vertical center posts 21 extending upwardly from the middle of thebase 18 are interconnected by a crossbar 22.

A wear pad 24 in accordance with the present invention is mounted on thecrossbar 22. Inclined wear pads 25 are mounted on arms 26 connected toand extending outwardly and upwardly from the ends of the crossbar 22.Inclined side posts 28 extend between the base 18 and the arms 26 forsupporting the latter. The basic difference between the transition andtroughing slide assemblies 14 and 15 is the angle of the inclined wearpads 25 with respect to the horizontal. The troughing wear pads and thesupporting arms 26 have a greater inclination for forming a deepmaterial conveying trough. The wear pads 24 and 25, which are formed ofa Teflon (trade-mark for polytetrafluoroethylene) composite, are similarto the pads disclosed by U.S. Pat. No. 6,854,592, issued Feb. 15, 2005.

The pad 24 can optionally include cylindrical or frusto-conical wearindicators of the types described in applicant's Canadian PatentApplication 2,327,646 and U.S. Pat. No. 6,854,593, respectively andwhich are incorporated herein by reference.

Referring to FIGS. 2 to 6, the wear pad 24 in accordance with thepresent invention is basically an elongated rectangular parallelepipedicbody with a flat, rectangular bottom surface 29 and a flat rectangulartop surface 30 over which the belt 1 slides. The top of the front andrear ends 31 (the leading and trailing ends in the direction of belttravel) of the pad 24 are beveled. Holes 32 in the pad 24 receive bolts33 for mounting the pad on the crossbar 22. The pad is spaced apart fromthe crossbar 22 by a pair of spacers 35. The bolts 33 extend through thespacers 35 and the crossbar 22. Nuts 36 are threaded onto the bottomends of the bolts 33 beneath the crossbar 22.

As mentioned above, when conveying liquid-containing material, e.g. inthe food processing industry, liquid tends to accumulate on the wearpads 24. The liquid literally sucks the belt 1 against the pads 24 whichcan slow down or stop the belt. Drag on the belt by the liquid isreduced by providing a plurality of grooves or channels 38 extendingbetween the leading and trailing edges (in the direction of belt travel)in the top of each pad 24. Liquid landing on the pads 24 is dischargedvia the grooves 38. While the dimensions of the pad 24 and the grooves38 are not critical, in a thirty inch long pad, three 0.25 by 0.25 inchgrooves 38 spaced slightly over an inch apart in the center of the padare effective. Of course, additional grooves with different dimensionscan be used in the top of the pad 24.

The wear pad 24 can also be mounted on the arms 26 in place of the wearpads 25.

It will be appreciated that while the wear pad of the present inventionhas been described in a particular environment, i.e. on a specific slideassembly, the wear pad can be used on different endless belt conveyorslides. Moreover, the number of grooves and the dimensions thereof canvary depending upon, inter alia, the belt width and the speed of belttravel over the pads.

Referring to FIG. 7, in another embodiment, a wear pad 125, inaccordance with the present invention, does not include grooves butotherwise has all of the same elements as wear pad 24 shown in FIGS. 3to 6 and described above and can be used in place of wear pad 24 onconveyor assemblies of the type shown in FIG. 1 and described herein.

Referring to FIGS. 8 to 14, in another embodiment, wear pad 32 andcrossbar 34 can be used in place of wear pads 24 and 25 and crossbar 22and arm 26 respectively in a conveyor assembly of the type shown in FIG.1 and described herein.

The wear pad 32 has a rectangular main top surface 36 which contacts thebelt 4. The top side edges 38 of the wear pad 32 are bevelled while thebottom surface 40 is rectangular. Two threaded holes 42 are provided inthe wear pad 32 for receiving a bolt 44. The bolt 44 is made from Teflonsuitable for use in the food industry. The bolt 44 includes a threadedsection 46 and a cylindrical head 46. The base 48 includes a bore 50therethrough for receiving a cotter pin 52.

The wear pad 32 can optionally include cylindrical or frusto-conical(indicated by 33) wear indicators of the types described in applicant'sCanadian patent no. 2,327,646 and U.S. Pat. No. 6,854,593 respectivelyand which are incorporated herein by reference.

The crossbar 34 is made from steel and is generally c-shaped in crosssection and includes two holes 54 (one toward each end of the crossbar34 in a similar fashion to holes 30 in crossbar 10) for receiving bolts44.

To mount the wear pad 32, a bolt 44 is screwed into each threaded hole42.

The wear pad 32 is then mounted on the crossbar 34 by dropping the base48 of the bolts 44 into the holes 54. A cotter pin 52 inserted into eachbore 50 prevents the wear pad 32 from being removed from the crossbar34.

With reference to FIGS. 16 and 17, return slides 17 in accordance withthe invention, can be used with a conveyor assembly of the typedescribed with reference to FIG. 1. Each return slide 17 includes anelongated steel base 30 having a generally C-shaped cross section. Thebase 130 is arcuate, i.e. upwardly bowed or convex when viewed from thefront or rear. A wear pad 131 mounted on the base 130 is also convexwhen viewed from the front or rear. Longitudinally extending grooves 133in the sides of the pad 131 receive inverted L-shaped brackets 134 forretaining the pad on the base 130. The brackets 134 are welded to thesides 135 of the base 130. The use of a return pad 131 with a topsurface, which is convex in a direction perpendicular to the directionof travel of the conveyor belt 1 beneath the pulleys 3 and 4substantially reduces wear on the edges of the belt. It will beappreciated that, when passing around the driven pulley 4, the belt 1tends to be concave even after the contents of the belt have beendropped. Thus, when it passes beneath the pulley 4, the belt 1 tends todefine a shallow, transversely extending inverted trough. The slide 131accommodates this belt configuration, reducing belt wear. It will alsobe appreciated that neither the base 130 nor the wear pad 131 need bearcuate. It is merely necessary for the top, belt engaging surface ofthe pad 131 to be bowed upwardly perpendicular to the path of travel ofthe belt 1 beneath the pulleys 3 and 4.

The base 130 is suspended from the sides 13 of the conveyor frame 10 byhangers 137. As best shown in FIG. 18, each hanger 137 includes a metalplate which is bent to define a large downwardly tapering, vertical topend 140, a central inclined web 142 and a smaller downwardly taperingbottom end 143. A rectangular flange 144 extends inwardly over the web142 at the top of the hanger. Holes 145 in the flange 144 receive boltsor screws (not shown) for suspending the hangers from the frame sides 2.

A keyhole slot 147 in the bottom end 143 of the hanger receives one end148 of a short bar 149, the other end 150 of which supports one end 151of the slide base 130. In the use position, the outer end 148 of the bar149 is horizontal, and the inner end 150 is inclined slightly upwardlyto match the slope of the base 130. The outer end 148 of the bar 149includes diametrically opposed flats, i.e. notches 153 for locking thebar in the slot 146.

Referring to FIG. 20, a novel clip 55 for locking the hanger 137 on thebar 149 includes a generally C or boomerang-shaped thin metal body witha horizontal top arm 56 and an inclined bottom arm 57. A threaded hole59 in the top arm 56 receives a screw 61, and a hole 62 in the arm 57 atthe bottom of the vertical corner 63 of the body receives a rivet 65.When the bar 149 is in the narrow bottom of the keyhole slot 147 and theclip 55 is in position with the top arm 56 extending over the bar, thebar 149 is locked in position and cannot escape from the hanger. Whenthe conveyor is being transported from one location to another, thereturn slide can be dislodged from the hangers 137, i.e. the bar 148 canbounce out of the slot 147 in the hanger. The clip 55 prevents suchaccidental release of the slide.

If the return slide or a portion thereof is to be replaced, the slidecan be removed from the hangers 137 by removing the screws 61 andlifting the slide. The bars 149 cause the clips 55 to pivot around therivets 65 to release the slide. The rivets 65 are long enough to permitthe clip to rotate, but sufficiently short that when rotated by the bars149 the bottom arm 57 of the clip remains in position covering thebottom end of the keyhole slot 147. When the bars 149 are inserted inthe slots 147 and lowered, the bars engage the arms 57 to cause theclips to rotate to the bar locking positions. The screws 61 are replacedin the holes 59 to lock the return slide in the hangers 137.

It will be appreciated by those skilled in the art to which the presentinvention relates that the clip 55 can be used with hangers forsuspending straight return slides or even roller assemblies from aconveyor frame.

1. A wear pad for use on a slide of an endless track conveyor beltcomprising an elongated body having a flat top surface for slidablysupporting a conveyor belt during travel of the belt over the topsurface between leading and trailing edges of the top surface; and aplurality of grooves in said top surface extending between the leadingand trailing edges of the body for discharging liquid falling onto thetop surface, whereby drag between the wear pad and the belt is reduced.2. The wear pad of claim 1, wherein said leading and trailing edges ofsaid body are beveled, and said grooves extend between said bevelededges.
 3. The wear pad of claim 2, wherein said grooves are parallel andspaced apart by a distance greater than their width.
 4. The wear pad ofclaim 3, wherein said grooves have square cross sections.
 5. The wearpad of claim 1, wherein said slide further comprises a crossbarsupporting the wear pad, the crossbar and wear pad extendingperpendicular to the path of travel of the endless belt; wherein aspacer between said pad and said crossbar spaces said pad from saidcrossbar; and wherein retaining means retain said pad and spacer on saidcrossbar.
 6. The wear pad of claim 5, wherein said pad, spacer andcrossbar each include a hole therethrough; a bolt extending through saidpad, spacer and crossbar; and a nut on said bolt for retaining saidbolt, pad and spacer on said crossbar.
 7. The wear pad of claim 1,further comprising a threaded hole therethrough, a syntheticfluorine-containing resin bolt insertable in said threaded hole, andlocking means for retaining said pad on said crossbar, wherein saidslide comprises a crossbar supporting the wear pad and extendingperpendicular to the path of travel of the endless belt, the top of saidcrossbar having a hole therethrough for receiving the resin bolt.
 8. Thewear pad of claim 7, wherein said bolt includes a threaded portion and ahead; and said locking means includes a hole through said head and acotter pin insertable in said hole.